With a young child enamored with vehicles of all types, I came up with the front end loader design shown when thinking of the perfect gift. Laser cut from 1/8" baltic birch with a few dowels for axles and pivots and held together with wood glue the result is pretty sturdy. The assembly measures about 11 inches long, 4 inches wide and 5 inches tall, has rolling wheels, pivoting lift arm, articulated body, and functional 6-bar linkage based bucket tilt mechanism. Design time in Solidworks was about 25 hours, cut time about 40 minutes, and assembly around 4 hours. Let me know what you think!
UPDATE: If you want to the .eps files to cut this yourself, you can get them on Ponoko in a variety of configurations at the link below (for a nominal fee). I have the original 1/8" baltic birch and modified 1/4" baltic birch plywood plans currently available. These plans require dowels to finish.
Front End Loader Plans on Ponoko
I have an all-laser-cut option that is a bit more complicated and doesn't quite move as nicely as the dowel version but is all-in-one for those not interested in buying dowels.
All-laser front end loader plans at Wooden Marvels.